Last week, James Middleton--brother of Kate; uncle of the future King of England--has been on a press blitz of New York.

For him, that mostly entails trying to avoid speaking about his sister, Kate, or the future King of England.

But he's the co-founder of a company that's looking for some pre-holiday publicity. To tee some up, he visited the set of ABC's "Good Morning America," sat amid the stock tickers on CNBC, and spoke with Brides magazine. Shockingly, Not talking about the royal family didn't go as planned.

GMA's panel of hosts asked him a bit about his company--called Boomf--but more about his relationship with his nephew, Prince George, the royal wedding, and the disturbingly intimate topic of his sister Kate's morning sickness. It's for this reason in part that the company for the first three months of its life hid--and considered disguising--Middleton's participation.

"You want to find your feet before people start scrutinizing it," Middleton tells Inc. "Now it's something I can't control."

In fairness, the company makes a product--Instagram images printed on marshmallows--that sounds so absurd it might be an artist-plotted metaphor for the current froth of Silicon Valley. Might be, that is, if it wasn't actually selling well--and at $25 per small box of treats to boot.

Around this time last year as the nascent Boomf geared up for 2013 holiday season, co-founder Andy Bell repped the company. But he's the more technical of the co-founders--Middleton is the product guy--and Bell says it became impossible to take meetings and correspond with potential partners, investors, and press without the man who created the square marshmallow and who set up Boomf's candy-making facility in Reading, around 40 miles from central London.

"There was a time when it was quite uncomfortable for us because were doing it under the radar," says Bell. "But we are not like a secret service operation. We couldn't keep it a secret forever."

After the 2013 Christmas rush, and roughly $100,000 in sales later, the duo decided custom marshmallows were indeed a viable business, and unmasked Middleton. With that, they subjected themselves to a whole new level of scrutiny: does the Duchess eat Boomf? Does Prince George? But the business has also kept growing fairly steadily, finding its niche as a customizable gift and gaining easy traction not just due to Middleton's notoriety, but also due to Instagram users sharing their Boomf creations. (On Instagram, of course.)

"We are lucky it's a very social business," Bell says. "People who like the product are often on Instagram, and then it reappears on social media. Plus, it's often a gift, which is given in a social setting. So we see in our statistics, for every one that's given, there are a couple more orders placed."

Middleton, 27, claims to have fallen into entrepreneurship after dropping out of college. As he tells Inc., school had always frustrated him. He's dyslexic, and from early on, says he knew he had a different manner of reaching conclusions than his peers. By college he grew sick of jumping through what he calls "wrong-sized hoops." After he left, he says, "the only person who would employ me without a degree was myself."

Actually, Middleton grew up steeped in entrepreneurship. In 1987--the very year he was born--his parents started Party Pieces, originally a mail-order party-supply company that found customers by distributing fliers to local day-care centers.

James Middleton's first endeavors included a custom-cake-baking company and one that makes kits for cake-making, called Cake Kit Company. With cakes in particular, he found significant frustration around delivery. The cakes were "wonderful, and fragile," Middleton says, and shipping costs to deliver them unharmed became "too expensive to justify ordering that cake."

Middleton became fixated on finding a customizable small sweet that could easily, and cheaply, make it through the postal service to customers' doorsteps, and through their mail slot.

"The science behind it was, 'well, a cupcake isn't going to last five minutes in the hands of a postman,'" Middleton half-jokes.

Meanwhile, a developer named Andy Bell who'd launched dozens of ideas for startups, had found a modicum of success with printing Instagram images on refrigerator magnets within Mint Labs. He, too, was fixated on what could be safely mailed. "In the future, as we move increasingly from normal commerce to e-commerce, one of the key affordance of what products should look like, and their shape, will be mail-ability," he says. He was impressed with Middleton's marshmallow idea, and its sturdy-but-feather-light packaging, and the pair set to work mid-last year.

If you're wondering: Boomf purportedly earned its place as the name of the venture as the duo's imagined noise a marshmallow would make if it could speak. Further evidence that, while both men take the business very seriously, neither lacks a sturdy sense of humor when it comes to their chosen product. In their stop by Inc.'s office Thursday, the pair was equal parts goofy and self-deprecating.

On the topic of starting up: "Marshmallows were just next on a list of stupid things we could print on," says Bell. Middleton chimed in on the difficulty of working with sugar to form square marshmallows--"They seem fluffy and nice but they are actually menaces!"--and the fact many orders include selfies. "You've never been challenged like this before," he mused. "'Should I eat my face?'"

It's not all laughs. The pair has big goals for expanding operations. Delivery of Boomf, which means a set of nine photo-printed marshmallows, already launched in the United States. And they're making a deal to set up automatic marshmallow-printing machines in New York stores.

Bell compares the strategy to that of Apple: "do manufacturing, retail, and have a big Web presence as well." He also compares--sans irony--Boomf to Pixar. "We want to wow people in ways they hadn't imagined, by bringing something from digital to physical."

At Inc., we couldn't resist asking one question about the world-famous family from which James hails. What did they think about his sugary venture?

"They probably wish I would stop talking about marshmallows," he said. "Because it's really all I talk about."